The present invention relates generally to fuel systems, and more particularly to an ecology system of a gas turbine engine.
A gas turbine engine typically uses a compressor section to deliver compressed air to a combustor section. The combustor section includes a plurality of combustors with each combustor including one or more fuel nozzles. In the combustor section, the fuel is mixed with the air and ignited (by igniters) thus resulting in combustion of the fuel-air mixture. This high-energy combustion exhaust gas is expanded through the turbine section to power the compressor section (which are connected via a common shaft) and exits the engine to produce thrust. In addition, a gas turbine engine can include a fan that is powered by the turbine section that can produce even more thrust.
After an aircraft has completed a flight, the gas turbine engine can be shut down by ceasing delivery of fuel to the combustor section. But unburned fuel can remain in the fuel nozzles and in the fuel lines leading thereto. This unburned fuel can evaporate into the atmosphere or flow out onto the tarmac, which is detrimental from both an economic and ecological standpoint. In addition, while the engine is still hot, the fuel remaining in the fuel nozzles can decompose thermally, thus leaving coke and/or varnish on the fuel nozzles, which impacts their function. Therefore, ecology systems have been developed to reclaim this unburned fuel.